Gasification process and apparatus



2 SHEETS-SHEET l Feb. 3, 1953 c. H. o. BERG GAsIPxcAToN PROCESS AND APPARATUS Filed June 5. 1947 S .m U D E P a E w m M w H 1 w m y m Y 5 a e w ,A Y p G G L l m SOLIDS FEEDER ZONE Feb. 3, 1953 c. H. o. BERG GASIPICATION PROCESS AND APPARATUS 2.- SHEETS--SHEET 2 Filed June 5, 194'? GQSIFCQTON PRODUCTS IN VEN TOR.

/7 TOE/Ey Patented Feb. 3, 1,953

GASIF'ICATION PROCESS AND APPARATUS Clyde H. O. Berg, Long Beach, Calif., assigner to Union Oil Company of California, Los Angeles, Calif., a corporation of California Application June 5, 1947, Serial No. 752,757

(Cl. Li8--86) 11 Claims.

This invention relates to a process and apparatus for` the production of gases and is particularly directed to a process and apparatus for the gasification of solid carbonaceous materials and materials which are generally used as solid fuels so as to produce combustible gases suitable for use either as fuels or in the synthesis of liquid fuels or organic chemicals. My eopending application Serial No. 723,311 is drawn to somewhat similar subject matter.

The production of gaseous fuels from carbonaceous materials generally employed as solid fuels is widely known in the art. Such production is carried out because of the fact that gaseous fuels have advantages over solid fuels in that they are clean, ash free, easily conveyed and handled, permit convenient firing of furnaces, and are applicable for use in internal combustion engines. In connection with steam generation or other application where furnaces are employed, gaseous fuels are adapted to extreme simplicity of control of temperature and heat supply. Combustible gases which are suitable for use as fuels may be manufactured from a wide variety of carbonaceous materials which are generally used as solid fuels. Such solid fuels include anthracite coal, bituminous coal, lignite, peat, petroleum coke, gas coke, charcoal, various types of woods and wood waste such as sawmill waste including sawdust and bark, tan bark, agricultural by-product such as straw, bagasse, and many other carbonaceous materials including materials which are basically cellulose.

One conventional manufactured gas, known as producer gas, is manufactured by the controlled primary combustion of coals, cokes, and other similar materials with primary air containing steam which yields a combustible gas Containing carbon monoxide, hydrogen, methane, and a considerable amount of nitrogen. Water gas is manufactured by the reaction of incandescent carbon with steam to form carbon monoxide and hydrogen and the process is generally carried out alternately with air blowing to heat the bed of incandescent carbon to a temperature sufficiently high that steam will readily react. Coal gas, which has a higher heating value than either producer gas or water gas, is produced by the distillation of coal in the absence of air. Also produced simultaneously with the coal gas, are considerable quantities of benzene and other aromatic hydrocarbons together with tars and pitch.

, The equipment which is employed in conventional gas producers, in general, comprises a vessel equipped with a grate near the bottom upon which the fuel bed is supported. Means are provided for introducing fresh fuel into the upper portion of the vessel and for removing ashes formed which fall through the grate. gases containing steam and oxygen are introduced below the grate and pass upwardly through the fuel bed and react therein with the carbcnaceous material. The product gases are removed from above the fuel bed. During operation considerable quantities of heat are generated in the oxidation zone just above the grate due to carbon oxidation heating the fuel to temperatures in the range of from 1500 F. to 3000io F. The entire weight of the charge is transmitted through the fuel in the oxidation Zone to be sup-` ported on the grate and therefore deformation and slagging of the ash occurs at temperatures where the ash becomes plastic, i. e., the softening point. The ash may flow under the resulting pressure and clog the grate halting the process.

The gasification rate increases with temperature and hence the highest possible temperature of operation is most desirable provided that this temperature is not so high as to exceed the softening point of either the Solid fuel or the ash. Gasii-lcation rate of a given apparatus is, therefore, limited by the softening point of the solid fuel being gasied or that of the resulting ash. For example, in the gasication of a bituminous coal having an ash which fuses at about 2000 F., a maximum gasification rate of only about six pounds per square foot per hour is possible without exceeding the softening point. The rate of gasification of a coal which has an ash fusion temperature of around 3000 F. is more than double that at 2000 F. In the case of gas producers of modern design, maximum gasification rates in general are limited under most favorable conditions to about 40 pounds per square foot per hour while in most gas producers the :maximum is between about l0 and 15 pounds per square foot per hour.

It is therefore an object of my invention as herein more fully described to provide a process for gasification of carbonaceous materials such as solid fuels which permits increased gasification temperatures and which is free from the conventional disadvantages which arise from slagging or fusion of the ash remaining following gasication of the carbonaceous materials.

A further object of my invention is to provide an improved gasification process which is adaptable to produce gases of widely variable composition and which gases are suitable for fuel, hydro- Reactant t genation, synthesis, such as Fischer-Tropsch synthesis depending upon demand.

It is an additi-onal object of my invention to provide a gasification process in which solid fuels may be gasied at maximum temperatures above the softening point at Which ash fusion and slagging normally prevent continuance of operation in conventional gasification processes permitting thereby a higher gas production rate per unit of apparatus.

In addition, it is a still further object of my invention to provide a gasiiication process having an increased heat efiiciency and adap-ted to produce gases from carbonaceous materials such as solid fuels which contain appreciable quantities of fines.

It is also an object of my invention to provide an improved gas production apparatus adapted to accomplish the above-mentioned objects.

Other objects and advantages of my invention Will become apparent to those skilled in the art as the description thereof proceeds.

Briefly, my invention comprises an improved process and apparatus for the production of combustible or synthesis gases at atmospheric and superatmospheric pressures from carbonaceous solids such asconventional solid fuels by reaction at high temperature with Water vapor and oxygen. The carbonaceous materials are introduced into the bottom of a vertical gasification Zone and forced upwardly therethrough counter-currently to downwardly flowing reactant gases containing water vapor and oxygen. B-y employing an upiiovv of carbonaceous materials and a doWnfloW of reactant gases, the high temperature oxidation zone wherein ash slagging generally occurs is maintained in the upper portion of the gasification kiln. The incandescent coal in the oxidation zone therefore is subjected to only a small fraction of the Weight of solid materials subjected to incandescent coal present in the conventional gas producers previously employed. Thus, temperatures of gasification considerably above the ash softening point may be employed in the gasification process according to my invention Without encountering difficulties inherent in conventional gasification processes. Solid fuels having abnormally low softening points or ash softening points such as between about l500 F. and 2000 F. which are therefore not applicable to gasification in conventional processes because of the low maximum permissible op-eration temperature may be quite ei"- ciently gasied in improved gasication process according rto my invention because gasification may be performed at temperatures above the softening point of either the fuel or Iash without usually encountered -difliculties In the apparatus according to my invention the temperature must app-roach the actual fluidity point of the ash lbefore trouble is encountered due to slagging. This makes possible markedly increased gasication temperatures which permit a considerable increase in gasification rates over those obtained in the conventional gas producers previously described.

The process and apparatus of gas production according to my invention has further advantages over conventional gas production processes and apparatus procedure employed. It is possible to carry out gas production according to my invention over a wide range of pressure and it is therefore possible to vary the composition of the gas produced over extremely wide ranges. For example, it is possible to produce a gas containing as high as about by volume of hydrogen which is applicable in hydrogcnation reactions, ammonia synthesis operations and for various other chemical uses. It is also possible to carry out the Water gas reaction in the apparatus of my invention and to obtain ya product gia-s having a mol ratio of hydrogen to carbon monoxide of about 1 to l if desired. By altering the operating conditions it is possible to produce gases having molar ratios of hydrogen to carbon monoxide which vary from about 1 to l to about 4 to 1 by introducing the proper quantity of steam into the gasification apparatus and by a judicious selection of operating pressure.

The reactant gases employed consist preferably of a mixture of steam and pure oxygen forming product gases which are virtually completely free of inert constituents which lower the heating value of the product gases when they are to be used as fuels. Such inert constituents also decrease the reactivity of the gases when they are to be used in synthesis reactions. It is possible to employ in the process of my invention reactant gases which comprise water vapor and air, water vapor and oxygen enriched air, or water vapor and fuel gas which contains excess oxygen. It is also possible to employ liquid Water instead of Water Vapor which may be introduced directly into the upper portion of the gasification kiln. A dual purpose is thus served in that the hot ashes present are cooled before being discharged from the gasification kiln in generating steam required in the process. An increased thermal efficiency results in permitting an efficient recovery of most of the heat contained in ashes formed.

The process according to my invention provides, depending upon the solid carbonaceous materials being gasiiied, varying quantities of oils, tars, and other distillates including hydrocarbon liquids and gases which are not required to be burned in the process and which are valuable by-products. The process of my invention is also adaptable to production of fuel gases which have heating values suiiiciently high to form excellent fuel gases. It is also possible to produce without further treatment synthesis gases applicable in the I. G.-Bergius or the Fischer-Tropsch synthesis processes. In these synthesis processes, a gas containing a molar ratio of hydrogen to carbon monoxide of around 2 to l is passed over an iron, nickel, or cobalt catalyst at temperatures between about 350 F. and 500 F., sometimes as high as 703 F. and

pressures between atmospheric to as high as,

about atmospheres to obtain hydrocarbons, alcohols, ketones, and a, wide variety of synthetic organic compounds. By employing specially compounded catalysts, waX-like hydrocarbon substances may be produced from synthesis gases manufactured by the process of my invention.

The fact that the process according to my invention permits production of synthesis gases which as produced have the required hydrogen to carbon monoxide ratio gives the process a decided advantage over the conventional synthesis gas production by the water gas reaction whereinl a gas containing an excess of carbon monoxide is obtained. A separate operation is required to generate suiicient hydrogen so that the water gas product may be graded to have the required hydrogen to carbon monoxide ratio.

My invention may be more readily understood by reference to the accompanying diagrammatic drawings in which,

Figure 1 illustrates a vertical cross section of one modification of the apparatus adapted to ac'- complish the process of gas production at pressures up to about 1,000 pounds per square inch or higher according to my invention, and

Figure 2 is a vertical cross section of the posi.- tive solids feeder employed to move solids upwardly through the apparatus. In order to facilitate a clear description of the apparatus, the solid carbonaceous material being gasified will be considered to be bituminous coal.

Referring to Figure l, the coal to be gasified is introduced by means of line I into a pressure lock which comprises valve II, coal hopper I2, and valve I3. The function of the pressure lock is to permit the introduction, by gravity, or coal into the gasification apparatus substantially without loss of pressure. Coal is introduced by means of line I0 through valve II which is open and falls into coal hopper I2 with valve i3 closed.

l Valve II s subsequently closed and valve I3 is opened causing coal hopper I2 to assume a pressure equal to that of the gasification apparatus. The coal contained within coal hopper I2 cascades therefrom through valve I3 by means. of line I4 into feed bin I5 formed below baffle I3 in the annular space between cooling jacket I@ and gasification kiln Il' and gasification vessel I8. The thus introduced coal fills the space in bin I5 from baiiie I 9 down to baiile 20 and further extends down and rests against baffle 2 I.

The coal to be gasified is introduced into a vertical conical gasification kiln having the larger diameter at the upper end for upward passage therethrough by means of a positive solids feeder, as hereinafter more fully described, positioned within the lower parts of gasication vessel IS. The coal is thus forced upwardly through gasiiication kiln I'I through zones E, D, C, B, and A, respectively. During passage upwardly therethrough, the coal is gasified by reaction at elevated temperatures with steam and oxygen so that a substantially complete conversion of the carbonaceous material present in the coal to gases is effected. The solid material discharged from Zone A in the upper portion of gasification kiln II comprises ashes of the coal being gasified and is substantially free of residual nongasied carbon.

The temperatures employed in the gasification reaction, especially within oxidation zone B, are quite high and in many cases approach the fusion point of the ash. The incipient fusion of the ash usually contained in the coal forms clnkers which are removed from the upper portion of zone A. These clinkers are broken into smaller pieces by means of rotary scraper 46 attached to shaft I'I which is introduced through seal 48 in the top of gasification vessel I8. By suitable means, not shown, shaft 47 and scraper 45 are rotated about a vertical axis at an angular velocity of between about 5 and 50 revolutions per minute. The broken pieces of clinker fall downwardly from the upper edge of gasification kiln I1 and impinge against the upper side of baie I9 and collect in the ash bin formed by the annular space between cooling jacket I6 of gasification kiln I'I and gasification vessel i8 above bafe I9. These pieces of clinker are continuously withdrawn by means of line 49 controlled by valve 50 and introduced into ash hopper 5 I. The clinkers are removed from ash hopper 5i by means of line 52 controlled by valve 53 and are disposed of in any suitable manner. Valves 50 and 53 together with ash hopper 5I comprise a pressure lock similar to that employed in introducing fresh coal into bin I5 andthe ashes,` or pieces of clinker if incipient fusion occurs, are introduced into ash hopper 5I when valve 50 is open and valve 53 is closed. Valve 50 is subsequently closed and the ashes are removed from ash hopper 5I through open valve 53.

In one modiiication of my invention it is possible to control the operation of the coal lock and the ash lock so that a semicontinuous introduction of coal and removal of ashes is attained. When the pressure of operation of the gasification apparatus is quite high, for example, above about 250 pounds per square inch, it may be advantageous to extend a pressure line 54 controlled by valve 55 from ash hopper 5I to coal hopper I5 so as to let one hopper partially depressure into the other. For automatic operation of the gasification apparatus, valves I l, I3, 50. 53 and 55 may be controlled by a suitable timing mechanisrn so as to open and close at the proper times and for the proper intervals to attain a given coal throughput.

During the upward passage of the coal through gasification kiln I'I, the coal is contacted by a reactant gas containing steam and oxygen passing downwardly therethrough. In zone A of gasification kiln EI the ashes or clinkers are cooled by direct heat exchange with the downwardly flowing reactant gases eifecting an efficient preheating thereof. The ashes removed from the upper portion of Zone A and subsequently discharged from gasication vessel I8 are removed therefrom at a temperature between about 300 F. and about 400 F. The reactant gases, containing steam and oxygen, are introduced into the upper portion of gasication kiln I3. Steam, at a pressure somewhat greater than that of the gasication operation pressure is introduced by means of line $3 controlled by valve 64 into header 555. A gas containing oxygen, which is preferably pure oxygen but which may comprise oxygen enriched air, air, or flue gas, is introduced by means of line Se controlled by valve E1 into header 55. The individual reactants are introduced at rates which are sufcient to give the required quantity and composition of steam and oxygen containing gases. The gases pass from Zone A downwardly into oxidation zone B at a temperature of about l000 F. to 1500 F.

Within oxidation Zone B al1 the heat generated in the process is formed by the reaction of the oxygen present in the reactant gas with unburned carbonaceous material present in the upwardly rising coal. This heat is formed principally by the following reaction:

A substantially complete conversion of carbon Another endothermic reaction simultaneously occurs between the carbon dioxide formed in oxidation zone B with the hot carbon present` in 2 reduction zone: C according tothe following rel-ationshipz' CO2 i#C- .2CO`-70,200'v B. t.. u.

Both. theA reactions of steam. and` carbon dioxide with incandescent carbon consume heatV and thus reduction zone C is considerably cooler than oxidation Zone B, but hot enough so that the reduc-- ing'. reactions progressfrapidly.

The hotv gases thus formed in reduction Zone C vpass downwardly through preheating and distillation zone D wherein theA incoming upwardly rising coal isipreheated. by the downwardly moving gases thus heating the coal to a temperature sufficient to eect the distillation of volatile matter. present in the coal. Liquid oils, tars, and hydrocarbon gases are distilled, from the coal in zone D at relatively lowv temperatures and' travel.

downwardly countercurrent into disengaging zone E; from. which the distilled tars and oils together with the product gases containingcarbon.

monoxide and hydrogen formed in oxidation zone B and reduction zone C are removed through perforationsv d present in grates 35 and 35a. These products of gasification areV removed from gasification kiln I3 by means of line 5l controlled by valve 58a and are sent to subsequent appa,- ratus, not shown, to eiect purification if desired or to be used Yin a furnace, internal combustion engine or in a synthesisreaction.

In some cases of operation with particular types of coal it is necessary to provide means for cooling solids4 feeder zone d5. In order to accomplish this, that portion of gasification vessel i8 below line 5T may be maintained full of water, liquid gasification products, or any other suitable medium whichcirculates through or evaporates at a sunicient rate to prevent overheating of the individual parts positioned in s-olids feeder zone 45. It is preferred to maintain a circulation of liquid through feeder zonev d5 and simultaneously allowing some of the circulated liquid to evaporate.

Referring now to Figure 2, the positive solids feeder comprises housing 22, guards Z3 and 2d, cylinder 25, piston 25, hydraulic cylinder 2 and hydraulic cylinder 28. Housing 22 comprises a curved member positioned within gasification vessel l 8 andintegrally attached thereto. Guards 23. and 24, which are integrally attached to cylinder 25, are constructed so as to have the same center of curvature as housing 22. Cylinder 25 is4 mounted on and free to rotate in an arc on vertical plane about trunnions 29. Hydraulic cylinder 23 is attached to the wall of gasification vessel I8 by means of attachment 3d and shaft 3| communicating with piston 32 is attached to the lower extremity of cylinder 25 by means of attachment 33. The introduction and removal of, hydraulic fluid from hydraulic cylinder 23 causes,y by the action imparted to piston 32 and shaft 3l, the movement of cylinder 2'5 in an arc on a vertical plane about trunnions 29 positioned at the center of curvature of housing 22 and guards 23 and 2li. Thus, when piston 32 is forced, by the introduction of hydraulic iiuid through inlet 35 into hydraulic cylinder 2S, to the right hand extremity of hydraulic cylinder 2S, the upper end of cylinder 25, in which is positioned piston 26, moves in the aforementioned arc to a position below the open mouth of bin i5 between baffle 2l and grate 35. When cylinder 25 has moved to a position below bin i 5, guard 23 comes into contactv with pilot valve 35 which causes the introduction of hydraulic fluid into the hydraulic cylinder 21 by means of inlet. 3.1. Piston 26 is pulled downwardly through cylinder 2 5` by shaft 25a creating an open volume in the upper portion of cylinder 25 into which cascades a portion of coal frornbin` l5. When piston 26 reaches the lower extremity' of itsA travel through cylinder 25 lug Bt attached to connecting rod 42 comes into Contact with pilot valve 38 which causes. the; introduction of hydraulic fluid into hydraulicv cylinder 28 by means of. inlet 39 thus causing cylinder 25 to rotate about trunnions 29 to a vertical position so that the. upper open end of cylinder 25 is positioned directly below Zone E of gasification kiln il. When cylinder 25 reaches the Vertical position, guard 2d cornes into contact with pilot valve 4i) which causes the introduction of hydraulic fluid into hydraulic cylinder 2.1` by means of inlet 4l causing piston 25 to moveupwardly through cylinder 25 and forces the fresh coal feed upward into zone E and consequently displacing in an upwardv direction the column of. solids present in zonesV A, B, C, and D of gasification kiln Il not shown. When piston 26 reaches the uppermost extremity of its travel through cylinder 25, pilot valve 38 is again tripped by means of lug 5I attached to connecting rod 42 causing the introduction of hydraulic fluid into hydraulic cylinder 23 through inlet 3'4 which in turn causes cylinder 26" to rotate inV an arc about trunnions 29 so that cylinder 25 is positionedbelow bin l5 in such a position as to receive a further quantity of fresh coal feed. The clearances between guards'- 23 and 2d attached to cylinder 25 and housing 22, the lower extremities of grates 35 and 35a, the lower extremity of baiile 2l and housing 22a are quite small, on the order of one-eighth of an inch or less. In order to equalize any pressure between zone E or bin I5 and solids feeder zone 45 due to the reciprocating action of piston 2G, line d3, controlled by valve #le is provided lconnecting solids feeder zone 5 with the remainder of the vessel above housing 22 and 22a.

In one modification of the apparatus of my invention no refractory brick' or other material is utilized on the inside of gasification kiln I'I. Insulation of the metal from the high temperatures of reaction generated in oxidation zone B is effected by a layerA of cooled coal which exists adjacent to the wall of gasification kiln I1. This layer of coal is cooled byv indirect heatf exchange with a suitable cooling huid such as for example water, oil or other, which is introduced into cool-` ing jackety it by means ofr line 58 and circulatedY through cooling jacket iS under a pressure substantially equal to that ofthe gasication operation. The cooling huid is introduced by means of line 58 equipped with expansion joint 59 into lower portion of cooling jacket l5, moves upwardly therethrough and isremoved from the upper portion thereof by means of line tu which is also equipped with expansion joint 6|. Suitable internal baies 57 may be positioned within cooling jacket I6 so as to direct the cooling fluid evenly over the entire outside area of gasification kiln l1. Cooling jacket l5 is provided with expansion joint 52 which is required because of the high internal temperature as compared with the temperature of the iiuid circulated through the cooling jacket.

The gasication process according to my invention is applicable to the production of producer gases which are suitable for furnace heating or for domestic use. The operation may be altered in such a` manner as to produce gases pounds per square inch or even higher.

i containing high concentration of carbon monoxide and hydrogen in the proper ratio which are l suitable feed gases for Fischer-Tropsch or I. G.-

Bergius synthesis operations. The apparatus of my invention may be modified to operate at pressures lower than atmospheric pressure in which case the construction of the apparatus may likewise be modified so as to eliminate gasication i Vessel I8 which is used at superatmospheric pressure as a fabricational expedient. Suitable re-l fractories may be employed within the gasification kiln if desired.

The advantage offered by superatmcspheric Apressure operation in contrast to the conventional gas producers which operate at near atmospheric pressure is very marked. When synthesis gases `are the desired products and a hydrogen to carbon monoxide molal ratio of about 2 to l is desired, it is possible to alter the pressure of gasiiication so as to reduce the quantity of carbon monoxide present in the product gases. Lower pressures displace the carbon dioxide-carbon monoxide equilibrium in favor of reduced quantities of carbon monoxide. Also the addition of an increased proportion of water Vapor in the reactant gases reduces the temperature of the gasication operation which in turn reduces the reactivity of the incandescent coke so that smaller quantities of carbon dioxide are reduced in the reduction Zone to carbon monoxide. This permits an effective means for the variation of the ccm- `position of the product gas by two factors; that is, by reduction of the pressure and the reduction of the gasification temperature. In general, the

process and the apparatus is applicable to operai tion in virtually any pressure such as from about pounds per square inch to as high as 1,000 In the production of synthesis gases having small quantities of carbon monoxide pressures in the range of from aboutl 10 to 200 pounds per square inch absolute are applicable to advantage,'and a pressure of operation which is representative as one of about 120 pounds `per square inch.

In the production of manufactured gases which are employed as fuels in furnaces, internal combustion engines, or other uses, the use of pressures higher than those employed in the production of synthesis gases is of advantage. Increased pressures are of advantage because .the formation of polyatcmic gases such as methane and carbon dioxide is favored. The presence in such a gas of quantities of methane results in a marked increase in the heating value and the theoretical ila-me temperature of the product gas.

4In the reduction zone where the gas is contacted with incandescent carbon in the absence of free `oxygen the carbon dioxide is reduced to carbon monoxide and the Water vapor or steam present in the reactant gas decomposes to provide further quantities of carbon monoxide and also hydrogen. The formation of carbon dioxide and of methane is exothermic and therefore reduces the quantity of oxygen required to supply heat to the process to between about 50 and 75 volume per cent of the oxygen required to effect the saine gasification at atmospheric pressure. The production of gases suitable as fuels may be carried out at pressures between about 10 and 1,000 pounds per square inch absolute or higher although pressures in the range of from about 100 to 400 pounds per square inch absolute are preferred. At these pressures the product gas may be cooled and scrubbed with water to effect an efficient removal of hydrogen sulfide or quanti- .substantially completely uties of undecomposed carbon dioxide. Such high pressure gasification produces a good fuel gas.

Since the gasification rate directly determines the number of gas producers which are required to supply a given quantity of gas and since the gasification rate is primarily limited by the maximum possible temperature of operation belowthe ash softening point, it is obvious that the process and apparatus of the present invention is much superior to the conventional processes and apparatus previously used because of the fact that increased gasification temperatures may be employed because gasification temperatures considerably higher than the softening point are possible Without the serious disadvantages normally encountered in the conventional gasification processes. The` oxidation zone which is the zoneof highest temperature and which frequently contains incandescent carbon heated to temperatures between 2,000 F. and as high as 3,500 F. carries very little weight of material above and does not rest on a grate thereby eliminating the conventional ash and fuel fusion and slagging problems. i

Carbonaceous materials which may be gasied and which include the solid fuels previously mentioned are preferably ground and fed to the gasication apparatus according to my invention in the form of small chunks or piecesof fromabout 0.25 inch to about 1.25 inches major dimensions. The apparatus is also capable .of handling and gasifying solid fuels which are introduced as granules havingdiameters as small as about 0.1 or larger than about 1.5 inches. v

I have further found that an apparatus containing a vertical kiln as a coking zone entirely analogous to that described for coal gasification may be employed under somewhat modiiied conditions in the coking of coals or other carbonaceous materials. When adapted to coking of coal, no steam is normally introduced into the apparatus with. the oxygen-containing reactant gas. The coking operation comprising a partial oxidation, is conducted at temperatures ranging from about 1500" F. to about 3000 F. depending upon the nature of coal being coked or of the coke desired. The product gases leaving the apparatus are removed at a temperature between about 900 F. and about 1500 F. The coal is introduced into the kiln in a similar manner to that described vheretofore through a reservoir containing liquids `formed in the coking operation or of water and 'is circulated through the feeder 4z'one to reduce temperatures of the feeder mechanism. The apparatus may likewise be operated under pressure as in the case of coal gasification. Coke formed 'is removed from the upper portion of the kiln similarly to the ash removal in gasification operations.

I-laving described and illustrated my invention and realizing that many modifications thereof may occur to those skilled in the art without departing from the spirit and scope of the follo-W- ing claims.

I claim:

1. An apparatus for the gasification of coall by reaction at elevated temperatures with oxygen and steam which comprises a vertical conical gasification kiln widening in an upward direction positioned within a gasification vessel adapted to withstand elevated internal pressures, a baffle separating the annular space between the gasification vessel and the gasification kiln into a'n illv upper lportion comprising yan ash bin and a vlower portion comprising a feed bin, pressure lock nreansfor introducing said coal into said feed bin `forsubsequent introduction into said gasification kiln Yto ybe gasified, pressure lock means for removing ashes from said ash bin, means for introducing reactant gases into .the upper part of said kiln, withdrawal means for removing product gases and liquids from the lower part of said kiln, and vpositive solids feeder means for passing said coal upwardly through said gasification kiln so as to maintain a bed of said coal at elevated temperatures in an oxidation zone in the upper portion of said gasification vessel where ,Said coal is subjected ,to a small fraction of the weight of vcoal present Within said kiln,

2,. A11 apparatus for the gasification of coal which comprises an upwardly widening vertical gasication kiln open at .the top, a jacket surrounding said gasification kiln, means for circulatinga coolant through said jacket, a gasification vessel surrounding said kiln and jacket, a baffle separating the annular space between the gasification vessel and the gasification kiln into an upper portion comprising an ash bin and a lower portion comprising a feed bin, pressure lock means for introducing said coal into said feed bin'while the latter is under superatmospheric pressure, solids feeder means within said 'vessel and 'below said kgasification kiln Aadapted to receive coal from'said feed bin and discharge Ait upwardly through said gasification kiln, pressure lock means for removing ashes `from said ash bin, means for introducing reactant gases comprising water vapor and oxygen into the top of l said gasification kiln, and means Vfor removing product liquids and gases Ifrom -the bottom of said gasification kiln.

3. An apparatus vfor the gasification of coal under superatmospheric pressures which comprises a yvertical gasification vessel, an upwardly widening, open topped Vertical metal gasification kiln supported within the upper portion of said gasification vessel, a cooling jacket surrounding said `gasification kiln, means for circulating a coolant through said cooling jacket, a baille separating the annular space between the gasification vessel and the cooling jacket into an upper portion comprising an ash bin and a lower por- 'tion comprising a feed bin, Apressure lock means AYfor introducing said coal into said feed bin, a solids feeder Vpositioned within said gasification vessel and below said gasification kiln, adapted to receive coal lfrom the feed bin and ,discharge `it lupwardly through said gasification kiln, means for breaking up clinkers and scraping ashes from Vthe top of said gasification kiln into said ash bin, pressure lock means for withdrawing ashes from said ash bin, means for introducing reactant gases comprising water vapor and oxygen at ccnt trolled Vrates into the top of said gasification kiln, means for removing product gases and liquids from the bottom of said gasication kiln just above said solids feeder, and means for maintaining said solids feeder comlpetely immersed in liquid comprising liquid products from the gasification kiln.

4. An apparatus according to claim 3 in which the solids feeder comprises a reciprocating piston adapted to be oscillated so that it is positioned alternately below the feed bin and the gasification kiln, means for lowering the piston when it is 'below the feed bin and raising it when it is positioned below the gasification kiln, and

12 guards oscillating with the ypiston vand substantially sealing the lower end of the gasification kiln while the piston is positioned below the feed bin and substantially sealing the lower end of the feed bin when the piston is positioned below the gasification kiln.

5. A continuous process for the gasification of coal under pressure which comprises introducing said coal by gravity through a pressure locking zone into a feeding zone which is completely immersed in a liquid coolant, forcing said coal from said feeding Zone upwardly Vthrough a gasification Zone comprising successively a preheating and distillation zone, a reduction zone, an oxidation Zone, and an ash zone, removing ashes from said ash zone through a pressure lock, in-

troducing reactant gases comprising water vapor and oxygen at controlled rates into said ash zone so as to preheat said reactant gases and cool said ashes, reacting the preheated reacting gases with residual carbonaceous material at superatmospheric pressure and a temperature above 1500* F. and above the softening point of the ash in said oxidation zone so as to effect a substantially complete conversion of the oxygen in said reactant gases to carbon dioxide, ycontacting the thus formed gas containing water vapor and carbon dioxide with hot carbon at a lower temperature in said reduction Zone `so as to reduce carbon dioxide to carbon monoxide and convert water vapor Vto gases containing essentially hydrogen and carbon vmonoxide and form said residual carbonaceous material, countercurrently contacting the coal in said preheating and distillation zone with the gases containing hydrogen and carbon monoxide formed in said reduction Zone so as to produce hydrocarbon gases and liquids from said coal and convert the coal to said hot carbon, `withdrawing gases and liquid hydrocarbons from the lower portion of said preheating and distillation Zone, retaining a portion of the 'liquids in said feeding zone to act as said coolant, and cooling said feeding zone by evaporation of a portion of the so-retained liquid.

6. A Yprocess according to claim v5 wherein the water added with said reactant gases is introduced at least in part as ,liquid water directly into said ash zone so as to cool said hot ashes by vaporization of the water.

'7. A process according to claim 5 wherein the coal is gasied under a pressure of between about 100 and 400 pounds per square inch absolute.

8. A process for vthe gasification of coal at a superatmospheric pressure, which comprises establishing a vertical gasification zone, introducing said coal into `a coal pressure locking zone at atmospheric pressure, raising the pressure in said zone to said superatmospheric pressure, passing the coal from said zone to the lower portion of said gasication Zone and through a liquid seal in the lower portion thereof, maintaining said gasification zone at said superatmospheric pressure, passinCr `the thus introduced coal upwardly through said gasification zone, introducing reactant gases comprising oxygen and steam into the upper portion of said gasification zone, passing said reactant gases downwardly through said gasication zone countercurrent to the upwardly rising coal therein, reacting said upwardly rising coal with said downwardly moving gases so as to produce product gases containing essentially carbon monoxide and hydrogen, and ashes, maintaining a maximum temperature in said gasification zone greater than the softening point of the material passing therethrough, passing said ashes from the upper portion of said gasification Zone into an ash discharge pressure locking zone at said superatmospheric pressure, reducing the pressure in said ash discharge pressure locking zone to atmospheric, discharging the ash therefrom, and removing said product gases substantially uncontaminated with air from the lower portion of said gasification zone just above said liquid seal.

9. A process for the gasication of coal at a superatmospheric pressure, which comprises establishing a Vertical gasification zone containing a coal preheating and distillation zone, introducing said coal into a coal pressure locking zone at atmospheric pressure, raising the presi sure in said Zone to said superatinospheric pres sure, passing the coal from said zone into said preheating and distillation zone and through a liquid seal in the lower portion thereof, maintaining said gasification zone at said superatmosphetric pressure, introducing reactant gases comprising water vapor and oxygen into the upper portion of said gasification zone, passing said coal upwardly through said gasication zone, passing said reactant gases down- 'f wardly through said gasification zone countercurrent to said coal therein, reacting said coal with said reactant gases so as to produce hot product gases containing essentially carbon monoxide and hydrogen, and ashes, at a maximum temperature above the softening point of solids passing therethrough, passing said hot product gases downwardly through said preheating and distillation zone countercurrent to the coal so as to preheat said coal and distil volatile matter therefrom to form gaseous and liquid distillates and cooled product gases, retaining a portion of said liquid distillates in the lower portion of said preheating and distillation Zone as said liquid seal, removing said gaseous and liquid distillates and said cool product gas substantially uncontaminated with air from the lower portion of said gasification Zone, passing said ashes from the upper portion of said gasication zone into an ash discharge pressure locking Zone at superatmospheric pressure, reducing the pressure in said ash discharge pressure locking Zone to atmopheric and discharging the ash therefrom.

10. A process of coal gasification at superatmospheric pressure, which comprises establishing a vertical gasification zone provided with a feeding zone, introducing said coal into a coal pressure locking Zone at atmospheric pressure, raising the pressure in said zone to said superatmospheric pressure, passing the coal from said zone into said feeding zone and through a liquid sealing medium therein, maintaining said gasification zone at said superatmospheric pressure, forcing said coal upwardly through said gasification Zone, introducing reactant gases comprising oxygen and steam into the upper portion of said gasication zone, reacting said coal in said gasication zone with said downwardly passing reactant gases at a maximum temperature above the softening point of the resulting ashes, to form hot ashes and hot product gases containing essentially carbon monoxide and hydrogen, employing said hot ashes to preheat said reactant gases, employing said hot product gases to preheat and distil from said coal volatile matter comprising hydrocarbon gases and liquids, passing said ashes from the upper portion of said gasification Zone into an ash discharge pressure locking zone at said superatmospheric pressure, reducing the pressure in said ash discharge pressure locking zone to atmospheric, discharging the ash therefrom, removing said product gases together with said Volatile matter from the lower' portion of said gasification zone, removing said product gases, hydrocarbon gases and liquids substantially uncontaminated with air, from a point just above said feeding Zone, cooling the solids in said feeding zone by submerging them in said liquid sealing medium and evaporating a portion of said liquid and circulating the remainder through a cooling circuit at a rate sufcient to prevent overheating thereof.

11. In a process of coal gasiiication according to claim 10, the improvement wherein said liquid submerging said feeder Zone comprises liquids produced from said coal.

CLYD'E I. O. BERG.

The following references are of record in the file of this patent:

UNTED STATES PATENTS Number Name Date 475,203 Colton May 17, 1892 687,656 Schneider Nov. 26, 1901 942,501 sbell Dec. 7, 1909 1,049,994 Chapman Jan. 7, 1913 1,146,776 Wallmann July 13, 1915 1,422,643 Wells July 11, 1922 1,440,828 Schafer July 3, 1923 1,469,628 Dundas Oct. 2, 1923 1,509,667 Catlin Sept. 23, 1924 1,547,213 Goeiita July 28, 1925 1,603,793 Olto Oct. 19, 1926 1,607,240 Davis et al Nov. 16, 1926 1,607,241 Davis et al Nov. 16, 1926 1,609,128 Richardson Nov. 30, 1926 1,639,356 Wallace Aug. 16, 1927 1,669,024 Runge May 8, 1928 1,689,202 Hare Oct. 30, 1928 1,698,907 Carr et al. Jan. 15, 1929 1,703,192 Hampton Feb. 26, 1929 1,709,838 Carrey Apr. 23, 1929 1,716,667 Schilling et ai June 11, 1929 1,734,970 Jenson Nov. 12, 1929 1,803,686 Andrews Mayl 5, 1931 1,824,282 Loughrey Sept. 22, 1931 1,826,007 Loebell Oct. 6, 1931 1,866,730 Sperr July 12, 1932 1,897,950 Eattin Feb. 14, 1933 1,901,159 Karrick Mar. 14, 1933 2,083,338 Kirby Mar. 10, 1936 2,088,679 Yamazaki Aug. 3, 1937 2,134,548 Danulat Oct. 25, 1938 2,238,792 Hanawalt Apr. 15, 1941 2,293,675 Martin Aug. 18, 1942 2,501,153 Berg Mar. 21, 1950 FOREIGN PATENTS Number Country Date 18,278 Australia Nov. 10, 1904 20,160 Australia of 1934 OTHER REFERENCES Haslam and Russell: Fuels and Their Combustion, 1st ed., pp. 552-556. New York, Mc- Graw-Hill, 1926. 

1. AN APPARATUS FOR THE GASIFICATION OF COAL BY REACTION AT ELEVATED TEMPERATURES WTH OXYGEN AND STEAM WHICH COMPRISES A VERTICAL CONICAL GASIFICATION KILN WIDENING IN AN UPWARD DIRECTION POSITIONED WITHIN A GASIFICATION VESSEL ADAPTED TO WITHSTAND ELEVATED INTERNAL PRESSURES, A BAFFLE SEPARATING THE ANNULAR SPACE BETWEEN THE GASIFICATION VESSEL AND THE GASIFICATION KILN INTO AN UPPER PORTION COMPRISING AN ASH BIN AND A LOWER PORTION COMPRISING A FEED BIN, PRESSURE LOCK MEANS FOR INTRODUCING SAID COAL INTO FEED BIN FOR SUBSEQUENT INTRODUCTION INTO SAID GASIFICATION KILN TO BE GASIFIED, PRESSURE LOCK MEANS FOR REMOVING ASHES FROM SAID ASH BIN, MEANS FOR INTRODUCING REACTANT GASES INTO THE UPPER PART OF SAID KILN, WITHDRAWAL MEANS FOR REMOVING PRODUCT GASES AND LIQUIDS FROM THE LOWER PART OF SAID KILN, AND POSITIVE SOLIDS FEEDER MEANS FOR PASSING SAID COAL UPWARDLY THROUGH SAID GASIFICATION KILN SO AS TO MAINTAIN A BED OF SAID COAL AT ELEVATED TEMPERATURES IN AN OXIDATION ZONE IN THE UPPER PORTION OF SAID GASIFICATION VESSEL WHERE SAID COAL IS SUBJECTED TO A SMALL FRACTION OF THE WEIGHT OF COAL PRESENT WITHIN SAID KILN. 